For large-scale grid-connected photovoltaic power generation systems, there are many solar cell components and the layout is scattered. Therefore, it is necessary to set up a necessary data monitoring system to monitor and control the equipment operation status and real-time meteorological data of the photovoltaic power generation system to ensure the photovoltaic power station. Stable and reliable operation under effective and convenient monitoring. At the same time, online analysis and research of the operating parameters, status and historical meteorological data of the photovoltaic power generation equipment system should also be carried out, which not only ensures simple, efficient and low-cost daily maintenance, but also predicts and forecasts the future power generation capacity of the system. The monitoring scope of the power station monitoring system includes the monitoring of solar cell arrays, grid-connected inverters, booster stations and station electrical systems. The main monitoring parameters include the DC output voltage, current and power of photovoltaic power generation units, inverters The voltage, current and power of the inlet and outlet, the output AC frequency of the inverter, the operating state and internal parameters of the inverter, the temperature and radiation intensity of each group of inverter units, and the 0.27kV/10kV/110kV step-up transformer and Various parameters of the station electrical system, etc., and realize the conventional control, protection and alarm of the 0.4kV/10kV/110kV step-up substation and the station electrical system.
Large-scale grid-connected photovoltaic power station projects cover a large area and require fewer operation and maintenance personnel. The isolation engineering measures between the station area and the outside world need to be simplified. For this reason, in addition to the necessary manual inspection and maintenance, it is also necessary to design a relatively complete safety defense. Monitoring system, such as wall infrared alarm monitoring system, CCTV screen monitoring system, etc.
1. Control device
(1) Monitoring system equipment
Due to the digital monitoring system used in photovoltaic power plants, this method is still in the stage of testing and promotion. Therefore, it is recommended to use system products that have successful application experience in digital control of 110kV and above booster stations or substations and have better performance and price. At the same time, The existing actual situation of the power station should be considered, and the selection of the control system should be convenient for operation management, reduce personnel training, and reduce engineering costs.
(2) Other control equipment
Under the premise of meeting the engineering design requirements of photovoltaic power plants, in principle, the selection of other control equipment should be mature and reliable, and the varieties of the whole station should be as unified as possible, so as to facilitate future operation management and daily maintenance and select substations of 110kV and above with successful application performance supplier of high-quality systems.
(1) DC system
A complete set of DC power supply system for maintenance-free lead-acid batteries shall be installed in the station. The DC system can provide reliable DC power for computer monitoring systems, circuit breakers, communication equipment and emergency lighting. The set of DC device is composed of maintenance-free battery, DC feeder screen, charging equipment and other devices. The charging equipment can automatically perform float charging and balanced charging according to the discharge capacity of the battery, and can run stably for a long time.
The DC system device is arranged in the main control room, and is monitored in the computer monitoring system by means of communication.
(2) AC non-stop power supply
A set of AC uninterrupted power supply is planned to be installed in the whole station to provide AC working power supply to monitoring host, five-proof host, network equipment, fire alarm system, CCTV system and other equipment.
3. Fire alarm system
Consider setting up a small fire alarm system in the 10kV/110kV booster station area and each inverter room, including detection devices (point or cable detectors, manual alarms), centralized alarm devices, power supply devices and linkage signals device etc. The centralized alarm device is arranged in the main control room of the booster station, and the detection point is directly connected to the centralized alarm device.
After a fire occurs in the equipment and rooms and each inverter room in the 10kV/110kV booster station area, the centralized alarm device immediately sends out sound and light signals, and records the fire alarm address and time. After confirmation, the corresponding fire protection facilities can be manually activated. Extinguishing. It is proposed to adopt the linkage control method to control the fans and air conditioners in the main control room and the power distribution room in the booster station, and monitor their feedback signals.
4. CCTV and fence security system
(1) CCTV and fence security system
According to the characteristics of large-scale grid-connected photovoltaic power plants, such as large area, scattered layout, and wide range of station boundaries, CCTV monitoring points can be set up in important parts such as booster stations, solar cell arrays, inverter sites, and surrounding walls. Select fixed focus or zoom monitoring lens according to the scope or characteristics of different monitoring objects; and set up an infrared alarm wall security system at the station wall. The video signal of each CCTV monitoring point is processed, distributed and transmitted to the monitor terminal in the main control room through the image broadband network, and the network is connected to form a unified CCTV monitoring system covering the scope of the project, and reserved for future Interface for expansion projects.
The set infrared alarm fence security system can realize alarm linkage with the CCTV surveillance system: when the fence security system alarms, the CCTV monitor terminal in the main control room will automatically switch to the surveillance image of the alarm location or area, and realize the sound alarm and Displays the name of the alarm location.
(2) All functions of CCTV system
In the CCTV system set up in the photovoltaic power station, through programming, the following main functions can be realized: ① normal inspection of the system; ② split screen monitoring; ③ alarm monitoring; ④ automation and intelligent tracking of the entire process can be realized.
Each monitor can automatically patrol each monitoring point in groups or individually according to the preset program; or manually monitor each important part at a fixed point, the system reserves a control interface, which can receive the control signal of the NCS system, and realize the automatic switching and tracking of the system operation. And provide output interface to drive long-time delay video recorder and other equipment.
(3) Main functions of wall security alarm system
The fence security alarm system is monitored by infrared radiation detection to prevent the entry of irrelevant personnel to ensure the safety of the equipment. When the main control room receives the active infrared radiation alarm, the alarm location can be determined, and the alarm situation can be observed through the CCTV camera installed nearby to determine whether it is a false alarm and confirm the on-site situation of the alarm area, so as to realize the positioning, tracking and monitoring of the alarm point. confirm.